Driving method of display panel and display device

Abstract

The present disclosure relates to the field of display technology, and provides driving methods of a display panel and a display device.

The invention claimed is: 
     
       1. A driving method of a display panel, comprising:
 detecting the display panel entering a variable refresh rate mode; 
 determining a target refresh rate range according to a refresh rate range of the variable refresh rate mode, wherein the target refresh rate range is from a minimum value of the refresh rate range to a target threshold; 
 determining whether a refresh rate of a current frame is within the target refresh rate range according to a frame signal of the current frame; and 
 in response to determining that the refresh rate of the current frame is within the target refresh rate range, adjusting a first level voltage of a scan signal in a blanking phase of the current frame, so that a voltage difference between the first level voltage and a second level voltage of the scan signal in the blanking phase is greater than a voltage difference between the first level voltage and the second level voltage of the scan signal in an active phase of the current frame. 
 
     
     
       2. The driving method of  claim 1 , further comprising:
 if determining that the refresh rate of the current frame is not within the target refresh rate range, keeping the first level voltage of the scan signal in the blanking phase equal to the first level voltage of the scan signal in the active phase. 
 
     
     
       3. The driving method of  claim 1 , wherein
 when the scan signal is at the first level voltage, in a pixel circuit of the display panel, except for that a driving transistor that drives a light emitting element of the pixel circuit to emit light is in an on state, all remaining transistors are in an off state; and 
 the scan signal acts on control terminals of the remaining transistors, and in the blanking phase, an adjusted first level voltage of the scan signal reduces a current through the light emitting element, through a parasitic capacitance generated by the remaining transistors in the pixel circuit. 
 
     
     
       4. The driving method of  claim 3 , wherein
 transistors in the pixel circuit are all PMOS transistors, the first level voltage of the scan signal is a high level voltage VGH, and the second level voltage of the scan signal is a low level voltage VGL; and 
 the adjusting the first level voltage of the scan signal in the blanking phase of the current frame comprises: 
 increasing the high level voltage VGH of the scan signal in the blanking phase. 
 
     
     
       5. The driving method of  claim 3 , wherein
 transistors in the pixel circuit are all NMOS transistors, the first level voltage of the scan signal is a low level voltage VGL, and the second level voltage of the scan signal is a high level voltage VGH; and 
 the adjusting the first level voltage of the scan signal in the blanking phase of the current frame comprises: 
 decreasing the low level voltage VGL of the scan signal in the blanking phase. 
 
     
     
       6. The driving method of  claim 3 , wherein the pixel circuit of each pixel of the display panel comprises:
 a first transistor, having a first terminal coupled to an initialization voltage terminal, a second terminal coupled to a first node, and a control terminal receiving a first scan signal; 
 a second transistor, having a first terminal coupled to a data line, a second terminal coupled to the first node, and a control terminal receiving a second scan signal; 
 a third transistor, having a first terminal coupled to an anode of the light emitting element, a second terminal coupled to the initialization voltage terminal, and a control terminal receiving a third scan signal; 
 a driving transistor, having a first terminal coupled to the anode of the light emitting element, a second terminal coupled to an anode power terminal, and a control terminal coupled to the first node; and 
 a storage capacitor, coupled between the first node and the anode power terminal, wherein when the scan signal is at the first level voltage, the driving transistor is turned on, and the first transistor, the second transistor, and the third transistor are turned off. 
 
     
     
       7. The driving method of  claim 6 , wherein the adjusting the first level voltage of the scan signal in the blanking phase of the current frame comprises:
 adjusting the first level voltages of the first scan signal, the second scan signal, and the third scan signal in the blanking phase, so that when the current frame enters the blanking phase, the first scan signal, the second scan signal, and the third scan signal are adjusted simultaneously. 
 
     
     
       8. The driving method of  claim 6 , wherein a working process of the pixel circuit in the active phase comprises:
 in a first reset phase, turning on the first transistor in response to the second level voltage of the first scan signal, and initializing, by an initialization voltage signal of the initialization voltage terminal, the control terminal of the driving transistor and the storage capacitor; 
 in a charging phase, turning on the second transistor in response to the second level voltage of the second scan signal, and charging, by a data voltage signal of the data line, the control terminal of the driving transistor and the storage capacitor; 
 in a second reset phase, turning on the third transistor in response to the second level voltage of the third scan signal, and initializing, by the initialization voltage signal, the anode of the light emitting element; and 
 in a display phase, turning on the driving transistor to drive the light emitting element to emit light. 
 
     
     
       9. A driving method of an OLED display panel, comprising:
 determining an initial power supply voltage of a data line according to an input data signal; 
 obtaining an adaptive adjustment voltage of the data line; 
 detecting a data signal processing phase in which the display panel is currently located; 
 If the display panel is currently in an active transmission phase, setting a power supply voltage of the data line to be the initial power supply voltage; and 
 If the display panel is currently in a blanking phase, setting the power supply voltage of the data line to be the adaptive adjustment voltage, wherein 
 the driving method further comprises setting the adaptive adjustment reference voltage by: 
 choosing a reference refresh frequency; and 
 for an i-th refresh frequency, obtaining the adaptive adjustment reference voltage corresponding to the i-th refresh frequency through a frequency switch process between the refresh frequency and the reference refresh frequency, wherein i ∈(1, n), and n is a category number of refresh frequencies different from the reference refresh frequency. 
 
     
     
       10. The driving method of  claim 9 , wherein the frequency switch process comprises:
 adjusting the adaptive adjustment reference voltage, so that the display panel does not flicker when switching between the reference refresh frequency and the i-th refresh frequency, and 
 recording a current adaptive adjustment reference voltage as the adaptive adjustment reference voltage corresponding to the i-th refresh frequency. 
 
     
     
       11. The driving method of  claim 9 , further comprising:
 after detecting the data signal processing phase in which the display panel is currently located, determining whether the data signal processing phase in which the display panel is currently located is consistent with the data signal processing phase at a previous moment; 
 if being consistent, keeping the current reference voltage unchanged; and 
 if being inconsistent, adjusting the current reference voltage. 
 
     
     
       12. The driving method of  claim 11 , the adjusting the current reference voltage if being inconsistent comprises:
 if the display panel is currently in the blanking phase but in the active transmission phase at the previous moment, using the adaptive adjustment reference voltage to replace the reference voltage at the previous moment; and 
 If the display panel is currently in the active transmission phase but in the blanking phase at the previous moment, using the initial reference voltage to replace the reference voltage at the previous moment. 
 
     
     
       13. The driving method of  claim 9 , wherein the determining the initial power supply voltage of the data line according to the input data signal comprises determining the initial power supply voltage of the data line according to an initial reference voltage and the input data signal. 
     
     
       14. The driving method of  claim 13 , wherein the obtaining the adaptive adjustment voltage of the data line comprises:
 obtaining an adaptive adjustment reference voltage; and 
 determining the adaptive adjustment voltage of the data line according to the adaptive adjustment reference voltage and the input data signal. 
 
     
     
       15. The driving method of  claim 14 , wherein the power supply voltage V DATA  of the data line meets a formula (1) of: 
       
         
           
             
               
                 
                   
                     
                       V 
                       DATA 
                     
                     = 
                     
                       GammaH 
                       - 
                       
                         
                           
                             GammaH 
                             - 
                             GammaL 
                           
                           
                             
                               2 
                               bit 
                             
                             - 
                             1 
                           
                         
                         × 
                         Data 
                       
                     
                   
                 
                 
                   
                     ( 
                     1 
                     ) 
                   
                 
               
             
           
         
         wherein, Data is an input parameter obtained according to the input data signal of the data line, bit is a preset coefficient, GammaH and GammaL are preset reference voltages, GammaH is a maximum reference voltage, GammaL is a preset minimum reference voltage, a fixed correspondence exists between a value of Data and the input data signal of the data line, and a value range of Data is from 0 to (2 bit −1); 
         the initial reference voltage comprises an initial GammaH value and an initial GammaL value; and 
         the adaptive adjustment reference voltage comprises an adaptive adjustment GammaH value and the initial GammaL value, or the initial GammaH value and an adaptive adjustment GammaL value, or an adaptive adjustment GammaH value and an adaptive adjustment GammaL value. 
       
     
     
       16. A driving method of a display device, comprising:
 generating a frame image signal, and outputting the frame image signal to the display device, the frame image signal comprising an active data region and a blanking region based on a time sequence; 
 detecting in real time whether a blanking interval of the frame image signal of a current frame starts; and 
 if starting, using the blanking interval of the frame image signal as a voltage transformation period, and changing an initialization voltage input to the display device during the voltage transformation period, to maintain a same average brightness with a change in frame rate. 
 
     
     
       17. The driving method of  claim 16 , wherein a duration of the voltage transformation period decreases as the frame rate increases, and the duration of the voltage transformation period increases as the frame rate decreases. 
     
     
       18. The driving method of  claim 16 , wherein the initialization voltage is switched from a preset voltage level to a regulated voltage level after the voltage transformation period starts, and the initialization voltage is switched from the regulated voltage level to the preset voltage level after the voltage transformation period ends. 
     
     
       19. The driving method of  claim 16 , wherein
 an increase or decrease value of the initialization voltage in the voltage transformation period of a current frame image signal is obtained, according to a duration of the frame image signal of the current frame, and based on a duration percentage of a preset voltage transformation period in the frame image signal; or 
 the initialization voltage is increased at least when the blanking region is displayed, to reduce an operating current of the display device, and an decrease value of the initialization voltage in the voltage transformation period of a current frame image signal, according to a duration of the active data region and a duration of the blanking region of the frame image signal of the current frame.